dsound: clamp smaller buffer sizes to 62.5 ms on Vista and later (cherry-pick of #782) #1008
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philburk
requested changes
Mar 14, 2025
src/hostapi/dsound/pa_win_ds.c
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| @@ -1733,7 +1733,12 @@ static void CalculateBufferSettings( unsigned long *hostBufferSizeFrames, | |||
| unsigned long maximumPollingPeriodFrames = (unsigned long)(sampleRate * PA_DS_MAXIMUM_POLLING_PERIOD_SECONDS); | |||
| unsigned long pollingJitterFrames = (unsigned long)(sampleRate * PA_DS_POLLING_JITTER_SECONDS); | |||
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Sorry Phil, I was in a rush and did not follow my standard procedure:
- Save the file before commit
- Check the diff before commit
- Check the diff before submitting the PR
- Check the diff after submitting the PR
- Check the CI results after submitting the PR
It should be OK now. The force pushes (1) fix the merge conflicts, (2) fix a missing {, (3) improve the short commit message.
src/hostapi/dsound/pa_win_ds.c
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| @@ -1768,6 +1773,7 @@ static void CalculateBufferSettings( unsigned long *hostBufferSizeFrames, | |||
| unsigned long adjustedSuggestedOutputLatencyFrames = | |||
| suggestedOutputLatencyFrames - userFramesPerBuffer; | |||
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RossBencina
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This works around a DirectSound limitation where input host buffer sizes smaller than 31.25 ms are basically unworkable and make PortAudio hang. The workaround is to impose a minimal buffer size of 2*31.25 ms on input-only and full-duplex streams. This is enough for the read cursor to advance twice around the buffer, basically resulting in de facto double buffering. This change was tested with `paloopback` under a wide variety of half/full-duplex, framesPerBuffer, and suggested latency parameters. (Note the testing was done on top of PortAudio#772 as otherwise paloopback is not usable.) NOTE: in the input+output case this patch also increases the output buffer size. Fixes PortAudio#775
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RossBencina
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philburk
approved these changes
Mar 24, 2025
This was referenced Mar 24, 2025
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see #782 for details and discussion.